From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Daniel Colascione Newsgroups: gmane.emacs.devel Subject: Re: [Emacs-diffs] trunk r114593: * lisp.h (eassert): Don't use 'assume'. Date: Fri, 11 Oct 2013 08:41:56 -0700 Message-ID: <52581C44.5070207@dancol.org> References: <52576305.9000703@dancol.org> <52579C68.1040904@cs.ucla.edu> <83iox4pa0w.fsf@gnu.org> <5257AB8C.40309@dancol.org> <83eh7sp6v0.fsf@gnu.org> <5257B489.2050609@dancol.org> <83k3hkrxao.fsf@gnu.org> <5257C27B.9090400@dancol.org> <83hacorvww.fsf@gnu.org> <5257CB20.4030809@dancol.org> <5257D36B.4090305@yandex.ru> <52581799.3060501@cs.ucla.edu> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1381506139 11350 80.91.229.3 (11 Oct 2013 15:42:19 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 11 Oct 2013 15:42:19 +0000 (UTC) Cc: emacs-devel@gnu.org To: Paul Eggert , Dmitry Antipov Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri Oct 11 17:42:24 2013 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1VUer9-0004gz-16 for ged-emacs-devel@m.gmane.org; Fri, 11 Oct 2013 17:42:23 +0200 Original-Received: from localhost ([::1]:55122 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VUer8-00018q-MB for ged-emacs-devel@m.gmane.org; Fri, 11 Oct 2013 11:42:22 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:51742) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VUeqy-00018Z-CM for emacs-devel@gnu.org; Fri, 11 Oct 2013 11:42:20 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VUeqp-0007yR-U5 for emacs-devel@gnu.org; Fri, 11 Oct 2013 11:42:12 -0400 Original-Received: from dancol.org ([2600:3c01::f03c:91ff:fedf:adf3]:48347) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VUeqp-0007yG-OV for emacs-devel@gnu.org; Fri, 11 Oct 2013 11:42:03 -0400 Original-Received: from c-69-181-250-160.hsd1.ca.comcast.net ([69.181.250.160] helo=dcolascione-mbp.local) by dancol.org with esmtpsa (TLS1.0:DHE_RSA_CAMELLIA_256_CBC_SHA1:256) (Exim 4.80) (envelope-from ) id 1VUeqn-000278-LC; Fri, 11 Oct 2013 08:42:01 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:24.0) Gecko/20100101 Thunderbird/24.0 In-Reply-To: <52581799.3060501@cs.ucla.edu> X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2600:3c01::f03c:91ff:fedf:adf3 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:164098 Archived-At: On 10/11/13 8:22 AM, Paul Eggert wrote: > This is a simple case. In other, more complicated cases, it > wasn't clear to me that the code with 'assume (COND)' was > faster -- it could be slower, as far as I could see, even > when COND was obviously side-effect free. I worry that at > least some of these cases reflect optimization glitches in > GCC, but perhaps in the long run these glitches will get > fixed. Do you have a particular case that concerns you, or an example of one of these optimizer glitches? I haven't seen a single instance of a correct, side-effect-free assume resulting in incorrect code generation.